1. Field of the Invention
The present invention relates to an image forming apparatus that forms an image by developing a latent image, transferring the developed image to a recording material, and fixing the transferred image.
2. Description of the Related Art
It has recently been desired that the number of printing per unit time in an image forming apparatus be increased to increase productivity (throughput). Japanese Patent Laid-Open No. 2009-8778 discloses a method of optimally controlling a developing condition, a transferring condition, a conveying condition, and a fixing condition for image formation on the basis of a printing ratio of an image and a kind of a recording material in order to increase throughput of an image forming apparatus, thus preventing a reduction of the throughput.
According to this method disclosed in Japanese Patent Laid-Open No. 2009-8778, since image forming conditions are changed depending on the kind of the recording material and the printing ratio, if a fixing temperature is changed during printing based on a single job including a plurality of pages, the quantity of heat applied to a single recording material may vary in a page which is being subjected to printing just after the temperature is changed. Specifically, since the quantity of heat applied to a leading end of each recording material differs from that applied to a trailing end thereof, for example, the gloss of each recording material may be uneven, namely, such printed products may vary in finished quality. Disadvantageously, the printed products with different finished qualities may be produced irrespective of the same job.